While Google ranks this website on the 2nd place after the hijacked Wikipedia page, Live.com, the by-default Microsoft search engine for users of Internet Explorer7, ranks this website at the 30th position.

A fun fact, but I wouldn't read too much into it. Every search engine has its own ranking algorithm. If you look at a few other popular and not-so-popular search engines they will place nooxml.org at anything from #3 (Yahoo) to around #100 (Ask.com). Random processes work like that: sometimes seemingly meaningful patterns will emerge for no reason. This is most likely just a coincidence, unless somebody can find more examples of active down-ranking of MS-critical websites at live.com.

So, It's almost 100% clear, that MS-critical websites are removed or at least down-ranked at live.com - I just tried to search by ooxml keyword and found, that nooxml.org is on first place ! Strange thing, right ?
But when I tried to search by pressing on link found in this post - I saw very different results, without nooxml.org :-/ Very strange, right ?
So, tried to found differences between these searches and found, that difference is default search engine language - I'm from Lithuania, so, live.com website as default is translated to Lithuanian language for me and shows completely different search results than live.com in English language !
I tested with other languages and noticed, that Microsoft filters mainly search results when language is set to English (en-us and en-gb), but not only - it seems in majority of languages (German, Russian, Polish, Lithuanian, etc) nooxml.org is in first place and results count is more than 2 200 000 but in searches in some languages, at least in English US, GB and IE produces completely different results - in en-us there are only about 26 000, in en-gb - about 800 000, etc.

So, look at these searches and see how Microsoft removes microsoft-critical web pages from live.com search:

Microsoft filters mainly search results when language is set to English

Now, that is strange. It's even less likely to be malicious, though. If they were actually trying to filter out criticism, they would certainly not limit that behavior to the US and Great Britain, right?

As anyone who's ever used the built-in search of Internet Explorer (the one you get if you click on "Search" in IE6), Microsoft rigs their search engine to bring up results favorable to them. See http://microsoft.toddverbeek.com/search.html :

For example, it used to be that a search for "linux" listed a tech article published by Microsoft as the #3 result, and a guide to dumping Linux for Windows as #4… pages that wouldn't have shown up anywhere near the top on less biased search services.